The claim of Dr. Hans Karabacek, scientist of considerable reputation, 10 be able to produce diamonds lof some size artiGcially recalls the various experiments of similar na~ ture which have been carried out with varying results in years ast. 3. H. Hannay and R. S, Marsden in 1680 and 1881 respectively made claims to having achieved the desired result, but this was not verified by Jothers_ who tried to repeat their methods, and the probability is that what they thought were small dia Jmond crystals were in reality car dorundum or carbide of silicon. Henri Molssan worked along the lines of combining terrify heat and great pressure 10 bring about a Tiquid state of carbon, which coes not ordinarily occur when at great temperature it changes from. the: solid to the gaseous form. His method was to mix pure iron with carbon obtained from the calcination sugar and rapidly to heat the whole in a crucible in an electric furnace, when after a few minutes a temperature of 4,000 degrees Centi-Jgrade was obtuined—a temperature at which the lime crucible itself commences to melt and the fron volatilizes in clouds. The dazzling jerucible is then lifted out and. plunged into cold water where it is: held until it sinks below a red leat.
The sudden cooling solidifies the outer skin of the molten metal hold ing the inner mass in an irresis.fble grip. The expansion of the inner Uquid produced an enormous pres-Jsure and under the stress the dis to a long treatment by which hot Jeque regia until no iron is left, when the remnant is found to consist chiefly of graphite with translucent flakes of chestnut-coloured carbon, hard black opaque carbon, and a [small quantity of transparent. colour-fess diamonds showing crystalline structure, which are ultimately iso-fiated by further treatment of the [black residue with various reagents. JArtifcial diamonds so made never could have influenced the market, [for none thas measured more then halt a millimetre across. Kara bacek's feat in making diamonds four millimetre in size indicates that he has made considerable progress along lines which were anti. ipated asa result of the earlier experiments of Moissan,
Text read from the printed page and cleaned; old type leaves the occasional error.